Automatic wheel grid

ABSTRACT

A wheel grid includes a crossbar configured to be coupled to a main boom of a wheel lift tow vehicle; two L-arms, each coupled to the crossbar at a respective pivot point and including an extension member and a wheel brace member; and a crossbar end coupled to each end of the crossbar and including a cantilevered portion, the crossbar ends each configured to engage a tire of a towed vehicle. The L-arms are configured to rotate into a stowed position in which each L arm is positioned under one of the cantilevered portions.

BACKGROUND

The present disclosure relates generally to vehicle towing. Morespecifically, the present disclosure relates to an automatic wheel gridcapable of supporting a wide range of track widths and tire sizes.

SUMMARY

One embodiment relates to a wheel grid including a crossbar, a firstL-arm, a second L-arm, a first crossbar end, and a second crossbar end.The crossbar is configured to be coupled to a main boom of a wheel lifttow vehicle. The first L-arm is rotatably coupled to the crossbar at afirst pivot point and includes a first extension member and a firstwheel brace member. The second L-arm is rotatably coupled to thecrossbar at a second pivot point and includes a second extension memberand a second wheel brace member. The first crossbar end is coupled to afirst end of the crossbar and is configured to engage a first tire of atowed vehicle. The first crossbar end includes a first cantileveredportion. The second crossbar end is coupled to a second end of thecrossbar and is configured to engage a second tire of the towed vehicle.The second crossbar end includes a second cantilevered portion. Thefirst and second L-arms are configured to rotate into a stowed positionin which the first wheel brace member is positioned under the firstcantilevered portion and the second wheel brace member is positionedunder the second cantilevered portion.

Another embodiment relates to a tow vehicle including a tow vehicleframe, a main boom coupled to the tow vehicle frame and extendingrearward from the tow vehicle frame, and a wheel grid rotatably coupledto the main boom by a rotation pin. The wheel grid includes a crossbarconfigured to be coupled to the main boom, an L-arm rotatably coupled tothe crossbar at a pivot point, the L-arm comprising an extension memberand a wheel brace member, and a crossbar end coupled to an end of thecrossbar and configured to engage a tire of a towed vehicle, thecrossbar end comprising a cantilevered portion. The L-arm is configuredto rotate into a stowed position in which the wheel brace member ispositioned under the cantilevered portion.

Another embodiment relates to a tow vehicle including a tow vehicleframe, a main boom coupled to the tow vehicle frame and extendingrearward from the tow vehicle frame, and a wheel grid rotatably coupledto the main boom by a rotation pin. The wheel grid is positionable in aneutral position in which a crossbar of the wheel grid is perpendicularto the main boom and rotatable at least 90 degrees clockwise and 90degrees counterclockwise from the neutral position about the rotationpin.

This summary is illustrative only and is not intended to be in any waylimiting. Other aspects, inventive features, and advantages of thedevices or processes described herein will become apparent in thedetailed description set forth herein, taken in conjunction with theaccompanying figures, wherein like reference numerals refer to likeelements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a wheel grid, according to an exemplaryembodiment.

FIG. 2 is a perspective view the wheel grid of FIG. 1 .

FIGS. 3A and 3B are side view diagrams of a tire being engaged by awheel grid.

FIG. 4 is a perspective view the wheel grid of FIG. 1 engaging a tire.

FIG. 5 is a plan view of the wheel grid of FIG. 1 in a loading position.

FIG. 6 is a plan view of the wheel grid of FIG. 1 transitioning from aloading position to an engaged position.

FIG. 7 is a plan view of the wheel grid of FIG. 1 in an engagedposition.

FIG. 8 is a plan view of the wheel grid of FIG. 1 in an over-rotatedengaged position.

FIG. 9 is a plan view of the wheel grid of FIG. 1 transitioning from anengaged position to a stowed position.

FIG. 10 is a plan view of the wheel grid of FIG. 1 in a stowed position.

FIGS. 11A and 11B are perspective views of the wheel grid of FIG. 1 .

FIG. 12 is a plan view of an interface between a main boom and the wheelgrid of FIG. 1 , according to an exemplary embodiment.

FIG. 13 is a perspective view of the interface of FIG. 12 .

FIGS. 14-16 are plan views of the wheel grid of FIG. 1 with overlaidalternative shaped L-arms.

FIG. 17 is a perspective view of the wheel grid of FIG. 1 lifting avehicle with chains, including protective belts positioned between thevehicle bumper and the wheel grid, according to an exemplary embodiment.

FIGS. 18 and 19 are perspective views of the wheel grid of FIG. 1 ,including one of the protective belts of FIG. 17 .

DETAILED DESCRIPTION

Before turning to the figures, which illustrate certain exemplaryembodiments in detail, it should be understood that the presentdisclosure is not limited to the details or methodology set forth in thedescription or illustrated in the figures. It should also be understoodthat the terminology used herein is for the purpose of description onlyand should not be regarded as limiting.

A wheel grid is a device that can be mounted to a tow vehicle to enabletowing of another vehicle. The wheel grid is configured to lift thefront or rear wheels of the towed vehicle off the ground by engaging therespective front or rear tires of the towed vehicle. This is generallypreferable to using a hook to engage the frame of the vehicle, which maycause damage to the towed vehicle or may be more difficult due to thedesign of the towed vehicle. For the purpose of brevity, the remainderof the present disclosure will discuss wheel grids engaging with thefront tires of towed vehicles. However, it should be understood that theembodiments disclosed herein may be used to tow a vehicle by lifting therear wheels instead.

A wheel grid is generally mounted to a main boom coupled to andextending out from the rear of the tow vehicle. The wheel grid includesa main crossbar, which is generally fixed in position and engages thefront sides of the front tires. The wheel grid may include two L-armsconfigured to rotate from a loading position, in which the L-arms can beinserted between the front wheels of the towed vehicle, to an engagedposition, in which the L-arms engage the rear sides of the front tires.The boom then lifts the wheel grid, and the front tires of the towedvehicle are lifted off the ground by the crossbar and the L-arms. Somewheel grids are designed such that the L-arms can rotate into a third,stowed position when no vehicle is being towed. In the stowed position,the L-arms are tucked underneath the tow vehicle so they do not extendbeyond the rear of the tow vehicle, creating a potential safety hazard.

An additional concern when designing wheel grids is the wide range oftrack widths (e.g., the distance between the two front tires) and tiresizes of various vehicles that may need to be towed. For example,compact sedans generally have narrower track widths and tire sizes thanfull-size pickup trucks. It is advantageous that a wheel grid is able tobe used to tow a wide variety of vehicle types.

According to an exemplary embodiment, a wheel grid includes a crossbarconfigured to be coupled to a main boom of a wheel lift tow vehicle; twoL-arms, each coupled to the crossbar at a respective pivot point andincluding an extension member and a wheel brace member; and a crossbarend coupled to each end of the crossbar and including a cantileveredportion, the crossbar ends each configured to engage a tire of a towedvehicle. The L-arms are configured to rotate into a stowed position inwhich each L arm is positioned under one of the cantilevered portions.

Referring now to FIGS. 1 and 2 , a wheel grid 100 is shown, according tosome embodiments. The wheel grid 100 includes a mounting bracket 102including an opening 104. The opening 104 is configured to receive a pinsuch that the mounting bracket 102 can be rotatably coupled to a mainboom of a tow truck by the pin. The mounting bracket 102 is coupled to acrossbar 106 that extends from a left end 108 to a right end 110. Thewheel grid 100 includes two L-arms 112 for engaging the front tires of atowed vehicle. Each L-arm 112 includes an extension member 114 coupledto a wheel brace member 116. The wheel brace member 116 may besubstantially straight and substantially perpendicular to the extensionmember 114. The L-arms 112 are rotatably coupled to the crossbar 106 atrotation points 118 (e.g., pivot points, etc.). Specifically, a proximalend of the extension member 114 is coupled to the rotation point 118 anda distal end of the extension member 114 is coupled to a proximal end ofthe wheel brace member 116. In FIG. 1 , the wheel grid 100 is shown inan engaged position, in which the wheel grid 100 may be engaged with thetires of a towed vehicle. The crossbar 106 engages the front of thefront tires of the towed vehicle, the extension members 114 extendrearward between the front tires, and the wheel brace members 116 engagethe rear of the front tires. The distance from the left end 108 to theright end 110 is shown as width W. The distance from the crossbar 106 tothe wheel brace members 116 is shown as distance D2.

FIG. 2 shows the wheel grid 100 in a stowed position, in which theL-arms 112 rotate approximately 90 degrees from the engaged positionsuch that the extension members 114 are substantially parallel andadjacent to the crossbar 106 and the wheel brace members 116 extendforward underneath the tow vehicle in a direction substantiallyperpendicular to the crossbar 106. In conventional wheel grids, thedistance from the rotation point 118 to the wheel brace member 116,shown as distance D3, may be greater than the distance from the rotationpoint 118 to the end 108 of the crossbar 106, shown as distance D1. Inthese conventional wheel grids, when the L-arms 112 rotate into thestowed position, the wheel brace members 116 may be positioned furtherfrom the center of the wheel grid 100 than the end 108 of the crossbar106. This allows the L-arms 112 to rotate into the stowed positionwithout the crossbar 106 interfering. However, in order to tow a widerange of vehicles, it may be advantageous to reduce the distance D2 sothat the wheel grid can be used to tow vehicles with smaller tires. Itis also advantageous to increase the distance D1, and more specifically,the width W of the crossbar 106, so that vehicles with wider trackwidths can also be towed. In order to increase the width W whiledecreasing the distance D1 (thereby reducing the distance D3), the wheelgrid 100 includes a crossbar end 120 at either end of the crossbar 106.The crossbar end 120 includes a cantilevered portion 122 that allows thewheel brace members 116 to rotate under the ends 108, 110 of thecrossbar 106. Thus, according to some embodiments, the wheel grid 100has a distance D3 from the rotation point 118 to the wheel brace member116 that is shorter than the distance D1 from the rotation point 118 tothe end 108 of the crossbar 106.

Referring now to FIGS. 3A and 3B, partial cross section views of twowheel grids 300 a, 300 b are shown engaging a towed vehicle 301,according to some embodiments. The wheel grid 300 a includes a crossbar306 a that is a distance D4 away from a wheel brace member 308 a. Thewheel grid 300 b includes a crossbar 306 b that is a distance D5 awayfrom a wheel brace member 308 b. Distance D5 is greater than distanceD4. When wheel grid 300 a engages the tire 302 of the towed vehicle 300,the tire 302 sits high enough that there is clearance between thecrossbar 306 a and the oil pan 304 and other components of theundercarriage of the towed vehicle 301. However, because the distance D5between the crossbar 306 b and the wheel brace member 308 b of the wheelgrid 300 b is larger, the tire 302 sits lower on the wheel grid 300 band the crossbar 306 b may contact and damage the oil pan 304 and othercomponents of the undercarriage of the towed vehicle 301. FIG. 4 shows awheel grid 100 with an L-arm 112 that is over-rotated such that thewheel brace member 116 contacts the tire 402 of a towed vehicle at acontact point 404 near the outside of the tire 402. It should beunderstood that “over-rotated” refers to the rotation of the l-arm 112such that the extension member 114 and the crossbar 106 form an anglegreater than 90 degrees. The contact point 404 is a distance D6 from thecrossbar 106, which is shorter than the length of the extension member114 due to the over-rotation of the L-arm 412. This may be necessary totow vehicles with smaller tires 402. The longer the extension member114, the more the L-arm 112 must over-rotate to contact the tire 402 atan acceptable distance D6. If the extension member 114 is too long, thewheel brace member 116 may contact the tire 402 at a contact point 404that is too close to the sidewall of the tire 402 or the extensionmember 114 may contact the sidewall of the tire 402, either of which candamage the tire 402.

FIGS. 5-11 illustrate the wheel grid 100 with the L-arms 112 rotatedinto various operational positions, according to some embodiments. Thewheel grid 100 is coupled to a boom 80, which may be coupled to andextend rearward from a tow vehicle. FIG. 5 shows the wheel grid 100 inthe loading position, with the wheel brace members 116 are perpendicularto the crossbar 106 and extending rearward and the extension members 114parallel and adjacent to the crossbar 106. To engage a vehicle to betowed, the tow vehicle backs up towards the towed vehicle and the wheelbrace members 116 are inserted between the front wheels of the towedvehicle until the crossbar 106 contacts the towed vehicle. Linearactuators 150 are configured to rotate the L-arms 112 to move thembetween the loading, engaged, and stowed positions. FIG. 6 shows thewheel grid 100 with the L-arms 112 in transition between the loadingposition and the engaged position. The rods 152 of the linear actuators150 retract into the cylinders 154, rotating the linkages 160 causingthe L-arms 112 to rotate. The linear actuators 150 may be, for example,electromechanical actuators, pneumatic actuators, or hydraulic actuatorsthat may be controlled via user input. In some embodiments, otheractuators or configurations may be used to cause the rotation of theL-arms 112. The arrangement of the linkages 160 allows the linearactuators 150 to be substantially within the footprint of the crossbar106 and enable at least 180-degree rotation of the L-arms 112 from thestowed position to the loading position. This, combined with thepositioning of the rotation points 118, allows the extension members 114to be substantially parallel and directly adjacent to the crossbar 106when in the loading position. When in the loading position, the wheelbrace member 116 may be substantially parallel and directly adjacent toone another. This may allow the wheel brace members 116 to more easilyfit between the tires of the towed vehicle, particularly when the towedvehicle must be engaged by the wheel grid 100 at an angle.

FIG. 7 shows the wheel grid 100 with the L-arms 112 rotated into anengaged position such that the wheel brace members 116 are roughlyparallel to the crossbar 106. The wheel brace members 116 may engage therear side of the front tires of the towed vehicle. The boom 80 can thenlift the wheel grid 100 causing the crossbar 106 and the wheel bracemembers 116 to lift the front of the towed vehicle by engaging the fronttires. It should be understood that one or more of the crossbar 106 orthe wheel brace members 116 may not contact the tire until the wheelgrid 100 is partially lifted. FIG. 8 shows the wheel grid 100 in anover-rotated engaged position. As discussed above, for towing vehicleswith smaller tires, a small amount of over-rotation may be necessary toreduce the distance D6 from the crossbar 106 to the contact point 404 ofthe tire on the wheel brace member 116. FIG. 9 shows the wheel grid 100with the L-arms 112 in transition between an engaged position and astowed position. The rods 152 of the linear actuators 150 continue toretract into the cylinders 154, rotating the linkages 160 causing theL-arms 112 to rotate further.

FIG. 10 shows the wheel grid 100 with the L-arms 112 in a stowedposition such that the extension members 114 are adjacent the crossbar106 and the wheel brace members 116 extend forward toward the towvehicle. The wheel brace members 116 pass under the cantileveredportions 122 of the crossbar ends 120. As discussed above, this allowsthe distance D3 from the crossbar 106 to the wheel brace members 116 tobe reduced while maintaining the width W of the crossbar 106. Becausethe wheel brace members 116 pass under the cantilevered portions 122 ofthe crossbar ends 120, the crossbar 106 does not interfere with therotation of the L-arms 112 into the stowed position.

FIGS. 11A and 11B show the wheel grid 100 rotated zero degrees andninety degrees, respectively, about a rotation pin 1104 inserted intothe opening 104 in the mounting bracket 102, according to someembodiments. The rotation pin 1104 rotatable couples the wheel grid 100to the main boom 80 to allow the tow vehicle to engage the tires of atowed vehicle from an angle. For example, it may not be possible to loada car parallel parked between two other cars with the crossbar 106 in astatic position perpendicular to the main boom 80. Rotation of the wheelgrid 100 allows the towed car to be engaged and pulled out of theparking spot at an angle. In some embodiments, the wheel grid 100 may beinserted under the center of a parallel-parked vehicle from the side,and the crossbar 106 may engage the rear of the front tires while thewheel brace members 116 engage the front of the front tires. The towedvehicle can be pulled out of the parking spot, set back down, andreengaged from the front to be towed away. In some embodiments, therotation of the wheel grid 100 relative to the main boom 80 may beactuated (e.g., electrically, hydraulically, or pneumatically actuated).In some embodiments, the wheel grid 100 rotates when it comes in contactwith a tire of a towed vehicle. The tire pushes the wheel grid 100 leftor right causing the rotation as the tow vehicle backs toward the towedvehicle. The wheel grid 100 may be able to rotate at least 90 degrees ineither direction (clockwise or counterclockwise) from the neutralposition in which the crossbar 106 is perpendicular to the main boom 80.

FIG. 12 shows a detent assembly 1200 that resists the rotation of thewheel grid 100 relative to the main boom 80, according to someembodiments. The detent assembly 1201 may be mounted to the crossbar 106by two fasteners 1202 (e.g., threaded fasteners, screws, shoulderscrews, etc.). The fasteners 1202 each extend through a respectiveclearance hole in a detent bracket 1204, such that the detent bracket1204 is slidably coupled (e.g., not threadedly coupled) to the fasteners1202. A spring 1206 is positioned around each of the fasteners 1202 andbiases the detent bracket 1204 toward the main boom 80. The fasteners1202 may be threadedly coupled to the crossbar 106, and a locknut 1208may be threadedly coupled to each fastener 1202 to hold the fastener1202 in position relative to the crossbar 106. When the wheel grid 100is in the neutral position (e.g., when the crossbar 106 is perpendicularto the main boom 80), the springs 1206 bias the detent bracket 1204 suchthat the detent bracket 1204 engages a detent flat 82 in the main boom80. This configuration resists the rotation of the wheel grid 100 untila rotational force on the wheel grid 100 overcomes the force of thedetent assembly 1100. The towed vehicle may thus be kept substantiallyin line with the tow vehicle unless a relatively strong rotational forceovercomes the force of the detent assembly 1100. The detent assembly1201 may also prevent or resist the rotation of the wheel grid 100 whenthe wheel grid 100 is in the stowed position to stop the wheel grid 100from swinging and potentially contacting the rear wheels or othercomponents of the tow vehicle. The main boom 80 includes a left portion84 and a right portion 86, each with a circular profile, which thedetent bracket 1204 contacts when the wheel grid 100 is rotated out ofthe neutral position. FIG. 13 shows a perspective view of the detentassembly 1200.

In some embodiments, the main boom 80 may include stops 88 to limit theoverall rotation of the wheel grid 100 in either direction. The stops 88may be positioned such that the heads of the fasteners 1202 contact thestops. Fine control of the maximum amount of rotation of the wheel grid100 can be achieved by adjusting the extension of the fasteners 1202away from the crossbar 106. For example, the fasteners 1202 can beloosened such that the heads of the fasteners 1202 are farther from thecrossbar 106. The heads of the fasteners 1202 will then contact thestops 88 on the main boom 80 at a lower amount of rotation. Conversely,the fasteners 1202 can be tightened such that the heads of the fasteners1202 are closer to the crossbar 106, and the wheel grid 100 will be ableto rotate further before the fasteners 1202 contact the stops 88.

FIGS. 14-16 show the wheel grid 100 with overlaid alternatively shapedL-arms 1412, to emphasize the advantages of the shape of the L-arms 112.The L-arms 1412 are designed with extension members 1414 that are notable to rotate into a parallel and adjacent position relative to thecrossbar 106. The L-arms 1412 may also include wheel brace members 1416that have a straight portion 1417 and an angled end 1418. The angledends 1418 cause the combined width W2 of the wheel brace members 1416 inthe loading position to be larger than the width W1 is the combinedwheel brace members 116 in the loading position. This makes it moredifficult to fit the wheel brace member 1416 between the tires of thetowed vehicle. FIGS. 15 and 16 show the wheel grid 100 and thealternatively shaped L-arms 1412 in a loading position engaging a largetire 401 and an over-rotated loading position engaging a small tire 403,respectively. As shown in FIG. 15 , because the straight portion 1417 ofthe wheel brace member 1416 is not perpendicular to the extension member1414, an area 1501 of interference is created. When engaging a towedvehicle with large tires 401, the area 1501 requires that the wheel gridis more centered on the towed vehicle. If the wheel grid is notcentered, the straight portion 1417 of the wheel brace member 1416 cancontact the sidewall of the tire 401. As shown in FIG. 16 , when towinga vehicle with small tires 403, the straight portion 1417 of the wheelbrace member 1416 may contact the sidewall of the tire 403 at a contactpoint 405 rather than making contact at the back of the tire at contactpoint 404. To avoid contact at the contact point 405, the L-arms 1412cannot over-rotate as much as the L-arms 112, which causes a towedvehicle with small tires 403 to drop lower into the wheel grid,potentially causing contact between the wheel grid and the undercarriageof the towed vehicle. Thus, in the case of a small tire 403 or a largetire 401, the L-arms 112 provide advantages over the alternativelydesigned L-arms 1412.

Crossbar Belting

In certain situations, it may be difficult or impossible to tow avehicle by engaging the tires with a wheel grid (e.g., wheel grid 100).For example, if the tires of the towed vehicle are damaged or the wheelsor tires are removed, the crossbar and L-arms may not be able toproperly engage and lift the vehicle. Instead, one or more chainscoupled to the crossbar may be used to lift the vehicle. The tow vehiclemay back toward the towed vehicle until the crossbar is approximatelyaligned with the front bumper of the towed vehicle. Then, a chain may becoupled to a hook on one side of the crossbar, coupled to the axle ofthe towed vehicle, and then coupled to a hook on the other side of thecrossbar. Alternatively, a separate chain may be coupled to each side ofthe crossbar and the axle. When the wheel grid is lifted, the chainslift the vehicle and the crossbar contacts or nearly contacts the frontbumper. In this towing arrangement, the crossbar may cause damage to thebumper if there is no protection in place between the bumper and thecrossbar, which is generally made of metal, such as steel or aluminum.

Referring now to FIGS. 17-19 , the wheel grid 100 is shown with aprotective belt 1700, according to some embodiments. The belt 1700 ispositioned around the crossbar 106 and provides a barrier between thecrossbar 106 and the bumper 1802 of the towed vehicle 1800. The belt1700 may be made of a flexible, relatively soft material that may reducescratches, dents, and other damage to the bumper 1802 that may occur ifthe bumper 1802 directly contacted the crossbar 106. For example, thebelt 1700 may be made from a rubber, plastic, or composite material. Thematerial may also be selected to provide a non-slip surface so that thebumper 1802 does not slide across the crossbar 106, which may furtherreduce the damage to the bumper. The belt 1700 may also protect thewheel grid 100 itself. For example, as shown in FIG. 19 , the belt maybe positioned around the L-arm actuator linkages 160, protecting thelinkages 160 as well as the crossbar 106 itself from damage caused bylifting the bumper 1802.

When a vehicle 1800 requires a chain lift (e.g., due to damage to thetires 1804), the L-arms 112 are rotated into the stowed position, asshown in FIGS. 17-19 . A belt 1700 is then installed on each side of thecrossbar 106. The belt 1700 includes an elongated body 1702 long enoughto wrap around the crossbar 106. The belt 1700 further includes a narrowportion 1704 that widens to a tab 1706 at one end of the belt 1700. Atthe other end of the belt 1700 is a slot 1708 sized to receive andretain the tab 1706. The slot 1708 may be, for example, a T-shaped slotwith a vertical portion 1710 and a horizontal portion 1712. To installthe belt 1700 on the crossbar 106, the belt 1700 is first positionedaround the chain hooks 111 near an outer end of the crossbar 106, asshown in FIG. 18 . In this area, the crossbar 106 may be relativelynarrow, allowing for more room to install belt 1700. Next, the tab 1706is inserted into the vertical portion 1710 of the slot 1708 by turningthe tab end of the belt 1700 ninety degrees from its natural position.Because of the shape and flexible material of the belt 1700, a user mayrotate the tab 1706 by hand. Once the tab 1706 has been fully inserted,the tab may be rotated ninety degrees back to its natural position, andthe narrow portion 1704 may be moved into the horizontal portion 1712 ofthe slot 1708. Because the tab 1706 is wider than the horizontal portion1712 of the slot 1708, the tab 1706 cannot be pulled through thehorizontal portion 1712, and the belt 1700 is retained around thecrossbar 106. Finally, the belt 1700 can be slid toward the center ofthe crossbar 106 into an installed position around the linkages 160, asshown in FIG. 19 . Because the crossbar 106 is wider in this position,the belt 1700 may fit snugly around the crossbar and be held in place byfriction. A second belt 1700 may be installed on the other end of thecrossbar 106.

Once the belts 1700 are in the installed position, the tow vehicle canback the wheel grid 100 up to a towed vehicle until the crossbar isroughly aligned with the bumper. Then, a user can install the chain 1720by coupling a first end of the chain 1720 to the hooks 111 on a firstside of the crossbar 106, coupling the chain 1720 to the axle or otherstructural component of the towed vehicle, and coupling the other sideof the chain 1720 to hooks 111 on the other side of the crossbar 106. Insome embodiments, separate chains 1720 may be used on each side of thecrossbar 106. Once the chains 1720 are installed, the wheel grid 100 canbe lifted, causing the chains to lift the vehicle 1800. As shown in FIG.17 , the belts separate the bumper 1802 of the towed vehicle 1800 fromthe wheel grid, protecting the bumper 1802, the crossbar 106, and thelinkages 160 from damage. To remove the belt 1700, the process isreversed. The vehicle is lowered to the ground and the chains 1720 areremoved. The belts 1700 are slid toward the end of the crossbar, and thetab 1706 is turned ninety degrees and pulled back through the verticalportion 1710 of the slot 1708. The tab 1706 may include an opening 1707that can be used to pull the tab 1706 when installing or removing thebelt 1700 or can be used to hook the belt 1700 in a storage location.

As utilized herein, the terms “approximately,” “about,” “substantially”,and similar terms are intended to have a broad meaning in harmony withthe common and accepted usage by those of ordinary skill in the art towhich the subject matter of this disclosure pertains. It should beunderstood by those of skill in the art who review this disclosure thatthese terms are intended to allow a description of certain featuresdescribed and claimed without restricting the scope of these features tothe precise numerical ranges provided. Accordingly, these terms shouldbe interpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the disclosure as recited inthe appended claims.

It should be noted that the term “exemplary” and variations thereof, asused herein to describe various embodiments, are intended to indicatethat such embodiments are possible examples, representations, orillustrations of possible embodiments (and such terms are not intendedto connote that such embodiments are necessarily extraordinary orsuperlative examples).

The term “coupled” and variations thereof, as used herein, means thejoining of two members directly or indirectly to one another. Suchjoining may be stationary (e.g., permanent or fixed) or moveable (e.g.,removable or releasable). Such joining may be achieved with the twomembers coupled directly to each other, with the two members coupled toeach other using a separate intervening member and any additionalintermediate members coupled with one another, or with the two memberscoupled to each other using an intervening member that is integrallyformed as a single unitary body with one of the two members. If“coupled” or variations thereof are modified by an additional term(e.g., directly coupled), the generic definition of “coupled” providedabove is modified by the plain language meaning of the additional term(e.g., “directly coupled” means the joining of two members without anyseparate intervening member), resulting in a narrower definition thanthe generic definition of “coupled” provided above. Such coupling may bemechanical, electrical, or fluidic.

References herein to the positions of elements (e.g., “top,” “bottom,”“above,” “below”) are merely used to describe the orientation of variouselements in the FIGURES. It should be noted that the orientation ofvarious elements may differ according to other exemplary embodiments,and that such variations are intended to be encompassed by the presentdisclosure.

The hardware and data processing components used to implement thevarious processes, operations, illustrative logics, logical blocks,modules and circuits described in connection with the embodimentsdisclosed herein may be implemented or performed with a general purposesingle- or multi-chip processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. A generalpurpose processor may be a microprocessor, or, any conventionalprocessor, controller, microcontroller, or state machine. A processoralso may be implemented as a combination of computing devices, such as acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. In some embodiments, particularprocesses and methods may be performed by circuitry that is specific toa given function. The memory (e.g., memory, memory unit, storage device)may include one or more devices (e.g., RAM, ROM, Flash memory, hard diskstorage) for storing data and/or computer code for completing orfacilitating the various processes, layers and modules described in thepresent disclosure. The memory may be or include volatile memory ornon-volatile memory, and may include database components, object codecomponents, script components, or any other type of informationstructure for supporting the various activities and informationstructures described in the present disclosure. According to anexemplary embodiment, the memory is communicably connected to theprocessor via a processing circuit and includes computer code forexecuting (e.g., by the processing circuit or the processor) the one ormore processes described herein.

The present disclosure contemplates methods, systems and programproducts on any machine-readable media for accomplishing variousoperations. The embodiments of the present disclosure may be implementedusing existing computer processors, or by a special purpose computerprocessor for an appropriate system, incorporated for this or anotherpurpose, or by a hardwired system. Embodiments within the scope of thepresent disclosure include program products comprising machine-readablemedia for carrying or having machine-executable instructions or datastructures stored thereon. Such machine-readable media can be anyavailable media that can be accessed by a general purpose or specialpurpose computer or other machine with a processor. By way of example,such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, orother optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to carry or storedesired program code in the form of machine-executable instructions ordata structures and which can be accessed by a general purpose orspecial purpose computer or other machine with a processor. Combinationsof the above are also included within the scope of machine-readablemedia. Machine-executable instructions include, for example,instructions and data that cause a general purpose computer, specialpurpose computer, or special purpose processing machines to perform acertain function or group of functions.

Although the figures and description may illustrate a specific order ofmethod steps, the order of such steps may differ from what is depictedand described, unless specified differently above. Also, two or moresteps may be performed concurrently or with partial concurrence, unlessspecified differently above. Such variation may depend, for example, onthe software and hardware systems chosen and on designer choice. Allsuch variations are within the scope of the disclosure. Likewise,software implementations of the described methods could be accomplishedwith standard programming techniques with rule-based logic and otherlogic to accomplish the various connection steps, processing steps,comparison steps, and decision steps.

It is important to note that the construction and arrangement of thewheel grid 100 and the systems and components thereof as shown in thevarious exemplary embodiments is illustrative only. Additionally, anyelement disclosed in one embodiment may be incorporated or utilized withany other embodiment disclosed herein. Although only one example of anelement from one embodiment that can be incorporated or utilized inanother embodiment has been described above, it should be appreciatedthat other elements of the various embodiments may be incorporated orutilized with any of the other embodiments disclosed herein.

The invention claimed is:
 1. A wheel grid comprising: a crossbarconfigured to be coupled to a main boom of a wheel lift tow vehicle; afirst L-arm comprising a first extension member and a first wheel bracemember, the first extension member rotatably coupled to the crossbar ata first pivot point; a second L-arm comprising a second extension memberand a second wheel brace member, the second extension member rotatablycoupled to the crossbar at a second pivot point; a first crossbar endcoupled to a first end of the crossbar adjacent a proximal end of thefirst crossbar end and configured to engage a first tire of a towedvehicle, the first crossbar end comprising a first cantilevered portionadjacent a distal end of the first crossbar end; and a second crossbarend coupled to a second end of the crossbar adjacent a proximal end ofthe second crossbar end and configured to engage a second tire of thetowed vehicle, the second crossbar end comprising a second cantileveredportion adjacent a distal end of the second crossbar end; wherein thefirst and second L-arms are configured to rotate into a stowed positionin which the first wheel brace member is positioned under the firstcantilevered portion and the second wheel brace member is positionedunder the second cantilevered portion.
 2. The wheel grid of claim 1,wherein: the first and second extension members are rotatably coupled tothe crossbar at respective proximal ends; a distal end of the firstextension member is coupled to a proximal end of the first wheel bracemember and a distal end of the second extension member is coupled to aproximal end of the second wheel brace member; and the first wheel bracemember extends substantially perpendicularly away from the firstextension member and the second wheel brace member extends substantiallyperpendicularly away from the second extension member.
 3. The wheel gridof claim 2, wherein in the stowed position, the first and secondextension members are positioned substantially parallel and adjacent tothe crossbar and the first and second wheel brace members extend in adirection substantially perpendicular to the crossbar.
 4. The wheel gridof claim 2, wherein the L-arms are configured to rotate into a loadingposition in which the extension members are substantially parallel andadjacent to the crossbar and the first wheel brace member issubstantially parallel and adjacent to the second wheel brace member. 5.The wheel grid of claim 4, further comprising a linear actuator coupledto one or more linkages, the linear actuator and the one or morelinkages configured to rotate the first L-arm approximately 180 degreesfrom the stowed position to the loading position.
 6. The wheel grid ofclaim 2, wherein the first and second wheel brace members aresubstantially straight.
 7. The wheel grid of claim 1, wherein thedistance from the first pivot point to the first wheel brace member isless than the distance from the first pivot point to a distal end of thefirst crossbar end.
 8. The wheel grid of claim 1, further comprising: amounting bracket coupled to the crossbar, the mounting bracketconfigured to be rotatably coupled to the main boom via a rotation pin;and a detent assembly coupled to the crossbar and configured to engage adetent flat on the main boom to resist the rotation of the wheel gridrelative to the main boom when the crossbar is perpendicular to the mainboom.
 9. The wheel grid of claim 8, wherein the detent assemblycomprises: a detent bracket slidably coupled to two fasteners, the twofasteners coupled to the crossbar; and two springs, each springpositioned around one of the two fasteners and configured to bias thedetent bracket away from the crossbar.
 10. The wheel grid of claim 9,wherein the fasteners are threadedly coupled to the crossbar and whereinthe detent assembly further comprises two locknuts, each locknutconfigured to restrict the rotation of one of the fasteners.
 11. A towvehicle comprising: a tow vehicle frame; a main boom coupled to the towvehicle frame and extending rearward from the tow vehicle frame; and awheel grid rotatably coupled to the main boom by a rotation pin, thewheel grid comprising: a crossbar configured to be coupled to the mainboom; an L-arm comprising an extension member and a wheel brace member,the extension member rotatably coupled to the crossbar at a pivot point;and a crossbar end coupled to an end of the crossbar adjacent a proximalend of the crossbar end and configured to engage a tire of a towedvehicle, the crossbar end comprising a cantilevered portion adjacent adistal end of the crossbar end; wherein the L-arm is configured torotate into a stowed position in which the wheel brace member ispositioned under the cantilevered portion.
 12. The tow vehicle of claim11, wherein: a proximal end of the extension member is rotatably coupledto the crossbar a distal end of the extension member is coupled to aproximal end of the wheel brace member; and the wheel brace memberextends substantially perpendicularly away from the extension member.13. The tow vehicle of claim 12, wherein in the stowed position, theextension member is positioned substantially parallel and adjacent tothe crossbar and the wheel brace member extend in a directionsubstantially perpendicular to the crossbar in a forward direction underthe tow vehicle frame.
 14. The tow vehicle of claim 11, wherein thedistance from the pivot point to the wheel brace member is less than thedistance from first pivot point to a distal end of the crossbar end. 15.The tow vehicle of claim 11, wherein the wheel grid is configured torotate at least 180 degrees about the rotation pin.